Aluminum alloy conductive rail profile and preparation method thereof

Abstract

The invention discloses an aluminum alloy conductive rail profile and a preparation method thereof. The aluminum alloy profile comprises the following components by mass percentage: Si≤0.4%, Fe≤0.2%, Cu≤0.05%, Mn≤0.05%, Mg≤0.6%, Cr≤0.1%, Zn≤0.1%, Ti≤0.1%, the remainder being Al and unavoidable impurities, the total amount of impurities being ≤0.1%, wherein Mg:Si=(1.4-1.5):1; the preparation process comprises: smelting, slag refining, degassing filtration, casting, homogenization treatment, surface impurity removal, extrusion, quenching, stretching straightening and aging. By adopting the invention, the aluminum alloy conductive rail profile has a tensile strength of ≥215MPa, a yield strength of ≥168MPa, an elongation of ≥11%, and a conductivity of ≥55.3IACS%, meeting the performance requirements of the conductive rail for the aluminum alloy profile.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy materials, and in particular to an aluminum alloy conductive rail profile and a preparation method thereof. Background Art

[0002] Medium- and high-strength conductive aluminum alloys can be used in products such as maglev rail trains, power transmission lines, satellite antennas, aluminum alloy electronic instrument chassis, and scientific research instrument chassis. Among them, Al-Mg-Si (6000 series) alloys have the advantages of stable conductivity, high strength, and good deformation resistance, and are widely used as load-bearing conductive aluminum alloys. However, the intermediate metal elements and micro-alloying elements added to the 6000 series alloys will cause the conductivity to decrease while strengthening the mechanical properties of the profiles, and the process flow of aluminum profile production will also affect the conductivity of the aluminum profiles. In addition, the current conductive aluminum alloys have a low elongation, which limits their application in guide rail profiles with complex shapes. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing an aluminum alloy conductive rail profile, which is suitable for preparing guide rails of complex shapes. The prepared aluminum alloy conductive rail profile has good mechanical properties and high conductivity.

[0004] The technical problem to be solved by the present invention is also to provide an aluminum alloy conductive rail profile obtained by the above preparation method.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for preparing an aluminum alloy conductive rail profile, comprising the following steps:

[0006] (1) The raw materials are put into a furnace for melting according to a formula, wherein the aluminum alloy conductive rail profile is composed of the following components by mass percentage: Si≤0.4%, Fe≤0.2%, Cu≤0.05%, Mn≤0.05%, Mg≤0.6%, Cr≤0.1%, Zn≤0.1%, Ti≤0.1%, the balance being Al and unavoidable impurities, the total amount of impurities being ≤0.1%, wherein Mg:Si=(1.4-1.5):1;

[0007] (2) slagging, refining, and standing the smelted raw materials;

[0008] (3) degassing and filtering the raw materials after standing, casting to obtain an aluminum alloy cylindrical ingot, and homogenizing the ingot; wherein the casting speed is 90 mm / min-95 mm / min, the homogenization temperature is 555° C.-565° C., and the time is 11 h-13 h;

[0009] (4) removing impurities from the surface of the aluminum alloy cylindrical ingot after homogenization;

[0010] (5) The aluminum alloy cylindrical ingot after surface impurities removal is heated and then extruded to obtain an aluminum alloy blank; wherein the extrusion temperature of the aluminum alloy cylindrical ingot is ≥ the extrusion temperature of the mold, and the extrusion process is constant speed extrusion, and the extrusion speed is 5m / min-10m / min.

[0011] (6) quenching and cooling the aluminum alloy blank, and then stretching and straightening it;

[0012] (7) The alloy blank after stretching and straightening is subjected to aging treatment.

[0013] As an improvement of the above technical solution, in step (3), the aluminum alloy cylindrical ingot after homogenization is subjected to strong wind cooling, cooled to 190°C-210°C and then cooled to room temperature by water cooling.

[0014] As an improvement of the above technical solution, in step (4), the surface de-impurity includes removing the outer surface of the aluminum alloy cylindrical ingot in a cold working state, and the thickness of the single-side removal is 3mm-5mm.

[0015] As an improvement of the above technical solution, in step (5), during the extrusion process, the upper temperature of the mold is 475°C-485°C, the temperature of the ingot barrel is 375°C-385°C, the temperature of the aluminum alloy cylindrical ingot is 480°C-490°C, and the discharge temperature of the aluminum alloy billet after extrusion is 522°C-530°C.

[0016] As an improvement of the above technical solution, in step (6), the quenching treatment includes a first stage of water mist quenching treatment and a second stage of strong wind quenching treatment; the first stage of water mist quenching treatment adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.6MPa-1.0MPa, and the second stage of strong wind quenching treatment adopts high-pressure strong wind cooling, and the wind pressure is 1.45kPa-1.6kPa, and the temperature of the aluminum alloy billet after leaving the quenching treatment is ≤100℃.

[0017] As an improvement of the above technical solution, in step (6), the stretching and straightening treatment adopts precise digital automatic stretching and straightening, the stretching rate is 1.3%-1.8%, and the stretching time is 18s-22s.

[0018] As an improvement of the above technical solution, in step (7), the aging treatment adopts a two-stage aging treatment process; the temperature of the first-stage aging treatment is 165°C-175°C, and the insulation time is 10.5h-11.5h; the temperature of the second-stage aging treatment is 195°C-205°C, and the insulation time is 2.5h-3.5h.

[0019] As an improvement of the above technical solution, in step (3), degassing adopts an online degassing device, and the hydrogen value of the raw material after degassing is ≤0.15ml / 100g;

[0020] The filtration is carried out using a double-layer ceramic filter plate, the porosity of the ceramic filter plate is 40ppi and 60ppi respectively, and the filtration is followed by drying for 1h-1.5h.

[0021] As an improvement of the above technical solution, the aluminum alloy conductive rail profile is composed of the following components by mass percentage: Si 0.34%-0.39%, Fe 0.08%-0.09%, Cu≤0.01%, Mn≤0.01%, Mg 0.5%-0.55%, Cr≤0.01%, Zn≤0.01%, Ti≤0.01%, and the balance is Al and unavoidable impurities, with a total impurity amount of ≤0.1%, wherein Mg:Si=(1.41-1.47):1.

[0022] Correspondingly, the present invention also provides an aluminum alloy conductive rail profile obtained by the above preparation method, wherein the aluminum alloy conductive rail profile has a tensile strength ≥217MPa, a yield strength ≥170MPa, an elongation ≥13.4%, and a conductivity ≥55.6IACS%.

[0023] The implementation of the embodiments of the present invention has the following beneficial effects:

[0024] The present invention optimizes and adjusts the content of alloy elements, controls the mass ratio of Mg element and Si element, reduces the content of impurity elements through processes such as dehydrogenation and refining, obtains high-purity and low-impurity raw materials, combines low-stress casting process, stress relief and segregation reduction process and double-stage aging process, so that aluminum alloy conductive rail profiles with complex shapes can be smoothly produced. The prepared aluminum alloy conductive rail profiles have a tensile strength of ≥215MPa, a yield strength of ≥168MPa, an elongation of ≥11%, and a conductivity of ≥55.3IACS%, meet the production requirements of the aluminum alloy conductive rail profiles, and have good comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a method for preparing an aluminum alloy conductive rail profile of the present invention;

[0026] Figure 2 The present invention is a schematic structural diagram of an aluminum alloy conductive rail profile. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with specific embodiments.

[0028] The embodiment of the present invention provides a method for preparing an aluminum alloy conductive rail profile. The aluminum alloy conductive rail profile consists of the following components by mass percentage: Si≤0.4%, Fe≤0.2%, Cu≤0.05%, Mn≤0.05%, Mg≤0.6%, Cr≤0.1%, Zn≤0.1%, Ti≤0.1%, the remainder being Al and unavoidable impurities, the total amount of impurities being ≤0.1%, wherein Mg:Si=(1.4-1.5):1.

[0029] Preferably, the aluminum alloy conductive rail profile is composed of the following components by mass percentage: Si 0.34%-0.39%, Fe 0.08%-0.09%, Cu≤0.01%, Mn≤0.01%, Mg 0.5%-0.55%, Cr≤0.01%, Zn≤0.01%, Ti≤0.01%, and the balance is Al and unavoidable impurities, with a total impurity amount of ≤0.1%, wherein Mg:Si=(1.41-1.47):1.

[0030] The alloy composition has a great influence on the mechanical strength and electrical conductivity of the profile. The main strengthening elements in the Al-Mg-Si alloy are Mg and Si, and the main strengthening phase is Mg 2 Si and excess free silicon. The tensile strength of the alloy increases with the Mg content in the alloy. 2 The content of Si and the content of excess free silicon increase, but at the same time its quenching sensitivity is also greater, the elongation and extrudability will decrease, thereby increasing the difficulty of the extrusion production process. Therefore, the content of Si is controlled below 0.4%, the content of Mg is controlled below 0.6%, and the mass ratio of Mg to Si is controlled at (1.4-1.5):1, so as to improve the extrusion performance while ensuring the strength of the aluminum alloy profile. Preferably, the content of Si is 0.34%-0.39%, the content of Mg is 0.5%-0.55%, and Mg:Si=(1.41-1.47):1.

[0031] In addition, during the casting process, Fe and Mn will preferentially react with Si to form AlFeSi or (FeMn) 3 SiAl 12 Intermetallic compounds, and Fe also has adverse effects on the extrusion performance and corrosion resistance of the alloy. Therefore, the Fe content is controlled below 0.2%, preferably, the Fe content is 0.08%-0.09%.

[0032] Ti has the functions of refining the casting structure and weld structure and reducing the cracking tendency, but too much Ti content will lead to a decrease in the extrusion surface quality. The Ti content is controlled below 0.1%, preferably Ti≤0.01%.

[0033] Cu has a certain solid solution strengthening effect, but at the same time it will reduce the corrosion resistance of the alloy, so the Cu content is controlled below 0.05%, preferably, Cu≤0.01%.

[0034] Mn can prevent the recrystallization process of aluminum alloy, increase the recrystallization temperature, and significantly refine the recrystallized grains. The Mn content is controlled below 0.05%, preferably, Mn≤0.01%.

[0035] Cr will increase the quenching sensitivity of the alloy, and the Cr content is controlled below 0.1%, preferably, Cr≤0.01%.

[0036] Zn is an impurity, and the Zn content is controlled below 0.1%, preferably, Zn≤0.01%.

[0037] like Figure 1 As shown, the preparation process includes the following steps:

[0038] S1 puts the raw materials into the furnace for melting according to the formula.

[0039] The raw materials are high-purity aluminum ingots with an aluminum content of 99.85% and high-purity low-impurity master alloys. The aluminum ingots are composed of the following components by mass percentage: Al ≥ 99.85%, Fe ≤ 0.12%, Si ≤ 0.08%, Mg ≤ 0.02%, Zn ≤ 0.03%, each of the other impurities ≤ 0.015%, and the total impurities ≤ 0.15%; the mass percentage of the Mg element in the high-purity magnesium ingot is ≥ 99.80%, and the Si element content of the high-purity silicon ingot is 10%-15%. The use of high-purity aluminum ingots and master alloys can reduce the damage of impurities to the organizational structure and reduce the impact on conductivity. The smelting temperature is 720℃-740℃.

[0040] S2 slags, refines and allows the smelted raw materials to stand.

[0041] After the second melting into liquid state, slag is removed once, using 99.99% high-purity argon gas for slag removal, the slag removal temperature is 720℃-740℃, the slag removal time is 12min-17min, and the slag removal gas volume is adjusted according to the height of the aluminum liquid waves.

[0042] The refining times are 2 times, the refining temperature is 730℃-740℃, and the refining time is 25min-30min.

[0043] Let it stand for 30-40 minutes, keeping the furnace door closed during the standing process.

[0044] S3 degasses and filters the raw materials after standing, casts them to obtain aluminum alloy cylindrical ingots, and performs homogenization treatment; wherein the casting speed is 90mm / min-95mm / min, and the casting speed is appropriately reduced. If the casting speed is too fast, the depth of the liquid cavity generated by the cooling of the aluminum alloy cylindrical ingot will increase, thereby forming tensile stress, resulting in the generation of defects such as cracks.

[0045] The degassing adopts an online degassing device, the hydrogen value of the water inlet is ≤0.4mg / 100g, and the hydrogen value of the raw material after degassing is ≤0.15ml / 100g, which increases the as-cast density and reduces the looseness of the as-cast structure.

[0046] The filtration is carried out using a double-layer ceramic filter plate, the porosity of the ceramic filter plate is 40ppi and 60ppi respectively, and the filtration is followed by drying for 1h-1.5h.

[0047] The temperature of the homogenization treatment is 555°C-565°C, and the time is 11h-13h; after the homogenization treatment, strong wind cooling is carried out to cool to 190°C-210°C, and then water cooling is used to cool to room temperature. The homogenization treatment is used to remove stress and reduce alloy segregation.

[0048] S4 removes impurities from the surface of the aluminum alloy cylindrical ingot after homogenization treatment.

[0049] The aluminum alloy cylindrical ingot after homogenization treatment is sawn into fixed lengths, and the outer surface of the aluminum alloy cylindrical ingot is removed in the cold working state. The single-side thickness removed is 3mm-5mm. The surface can be removed by lathe or online peeling equipment to remove the oxide layer, segregation layer and impurities on the surface of the aluminum alloy cylindrical ingot, which can reduce the impact on the profile structure.

[0050] S5 heats the aluminum alloy cylindrical ingot after surface impurities are removed and then extrude it onto a machine to obtain an aluminum alloy blank.

[0051] During the extrusion process, the temperature of the die on the machine is 475℃-485℃, the temperature of the ingot barrel is 375℃-385℃, and the aluminum alloy cylindrical ingot is preheated to 480℃-490℃ before being put on the machine. The temperature level during the extrusion process is maintained by heating the workpiece, which is beneficial to reduce temperature loss, improve the flow stability of the extruded metal, and reduce the influence of pressure fluctuations caused by temperature on the grain size of the organization. The extrusion speed is 5m / min-10m / min, and constant speed extrusion is adopted throughout the process. The discharge temperature after extrusion is 522℃-530℃.

[0052] S6: quenching and cooling the aluminum alloy blank, and then stretching and straightening it.

[0053] The quenching treatment includes a first stage of water mist quenching treatment and a second stage of strong wind quenching treatment; the first stage of water mist quenching treatment adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.6MPa-1.0MPa to prevent coarse grains and promote the formation of supersaturated solid solution; the second stage of strong wind quenching treatment adopts high-pressure strong wind cooling, and the wind pressure is 1.45kPa-1.6kPa, and the temperature of the aluminum alloy billet out of the quenching treatment is ≤100°C.

[0054] The stretching and straightening process uses precise digital automatic stretching and straightening, with a stretching rate of 1.3%-1.8% and a stretching time of 18s-22s.

[0055] S7 performs aging treatment on the alloy blank after the stretching and straightening treatment.

[0056] The aging treatment adopts a two-stage aging treatment process; the temperature of the first-stage aging treatment is 165℃-175℃, the holding time is 10.5h-11.5h, and the temperature of the second-stage aging treatment is 195℃-205℃, the holding time is 2.5h-3.5h. The first-stage aging treatment can promote matrix coherence, cause lattice distortion, lead to increased dislocation rate, and increase electron scattering; the second-stage aging treatment increases the aging temperature to allow the alloy to enter a deep aging body, gradually eliminate coherence, reduce lattice distortion, evenly reduce electron scattering, and improve conductivity.

[0057] The present invention also provides an aluminum alloy conductive rail profile, which is prepared by the above preparation method. Figure 2 As shown, the aluminum alloy conductive rail profile includes an upper horizontal rail 1, a vertical rail 2 and a lower horizontal rail 3. A heat sink 4 is provided on the vertical rail 2, a T-slot 5 is provided at the bottom of the lower horizontal rail 3, and a reinforcing rib 6 is provided between the bottom of the upper horizontal rail 1 and the vertical rail 2. The reinforcing rib 6 is provided above the heat sink 4. The reinforcing rib 6 is symmetrically arranged on the left and right sides of the vertical rail 2. The heat sink 4 is evenly distributed on the vertical rail 2 and symmetrically arranged on the left and right sides of the vertical rail 2. The force is evenly applied, which is convenient for extrusion molding. The ratio of the thickness to the length of the heat sink 4 is 1 / 7-1 / 5. The setting of the T-slot 5 can further increase the connection reliability of the aluminum alloy conductive rail, and the conductive rail has good heat dissipation effect and high mechanical strength.

[0058] Compared with the traditional I-shaped rail structure, the aluminum alloy conductive rail profile in the embodiment of the present application has high dimensional requirements, and the arrangement of the reinforcing ribs, heat sinks and T-slots requires the aluminum alloy to have better extrusion performance. To this end, the present invention improves the extrusion performance of the profile by adjusting the formula and process, so that the aluminum alloy conductive rail profile in the embodiment of the present application can be extruded smoothly. At the same time, the overall dimensional accuracy is improved through water mist cooling and strong wind cooling, and the conductive performance is further improved through double aging.

[0059] The preparation method of an aluminum alloy conductive rail profile of the present invention is further described in detail below in conjunction with specific embodiments.

[0060] Example 1

[0061] The aluminum alloy conductor rail profile is composed of the following components by mass percentage: Si 0.4%, Fe 0.1%, Cu 0.02%, Mn 0.02%, Mg 0.6%, Cr 0.05%, Zn 0.02%, Ti 0.02%, the balance is Al and unavoidable impurities, and the total amount of impurities is ≤0.1%.

[0062] The preparation process includes the following steps:

[0063] (1) A high-purity aluminum ingot with an aluminum content of 99.85% and a high-purity, low-impurity master alloy are placed in a furnace according to the element composition ratio, and the temperature is raised to 730° C. for smelting.

[0064] (2) The smelted raw materials are put into the furnace for a second time to melt into liquid state, and then slag is removed once with 99.99% high-purity argon gas at a slag removal temperature of 730°C for 15 minutes; after slag removal, refining is carried out, the first refining temperature is 735°C for 20 minutes, the second refining aluminum liquid temperature is 740°C for 20 minutes, and the aluminum liquid is allowed to stand for 30 minutes after refining.

[0065] (3) Degassing the raw materials after standing by using an online degassing device, wherein the hydrogen value of the raw materials after degassing is ≤0.15 ml / 100 g; filtering the degassed raw materials, wherein the porosities of the double-layer ceramic filter plates are 40 ppi and 60 ppi, respectively, drying for 1 hour after filtration, casting at a casting speed of 93 mm / min to obtain an aluminum alloy cylindrical ingot, and homogenizing at 558° C. for 13 hours; after homogenization, cooling to 200° C. by strong wind cooling, and then cooling to room temperature by water cooling.

[0066] (4) The aluminum alloy cylindrical ingot after homogenization treatment is sawn into fixed lengths, and the outer surface of the aluminum alloy cylindrical ingot is removed by lathing in a cold working state, and the thickness of the removed single side is 4 mm.

[0067] (5) The aluminum alloy cylindrical ingot after surface impurities removal is heated and then put into extrusion machine. During the extrusion process, the temperature of the mold on the machine is 485°C, the temperature of the ingot barrel is 385°C, and the aluminum alloy cylindrical ingot is preheated to 490°C before being put into the machine. The extrusion speed is 8.2m / min. Constant speed extrusion is adopted throughout the process. The discharge temperature after extrusion is completed is 530°C.

[0068] (6) The aluminum alloy blank is subjected to quenching treatment. The first stage of water mist quenching treatment adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.8 MPa. The second stage of strong wind quenching treatment adopts high-pressure strong wind cooling, and the wind pressure is 1.5 kPa. The temperature of the aluminum alloy blank after leaving the quenching treatment is ≤100°C; after quenching, it is stretched and straightened, and precise digital automatic stretching and straightening are adopted. The stretching rate is 1.3% and the stretching time is 22s.

[0069] (7) The alloy blank after the stretching and straightening treatment is subjected to a double-stage aging treatment, wherein the temperature of the first aging treatment is 170°C, the holding time is 11 h, and the temperature of the second aging treatment is 200°C, the holding time is 3 h.

[0070] Example 2

[0071] The aluminum alloy conductor rail profile is composed of the following components by mass percentage: Si 0.35%, Fe 0.1%, Cu 0.02%, Mn 0.02%, Mg 0.5%, Cr 0.05%, Zn 0.02%, Ti 0.02%, the balance is Al and unavoidable impurities, and the total amount of impurities is ≤0.1%.

[0072] The preparation process includes the following steps:

[0073] (1) A high-purity aluminum ingot with an aluminum content of 99.85% and a high-purity, low-impurity master alloy are placed in a furnace according to the element composition ratio, and the temperature is raised to 730° C. for smelting.

[0074] (2) The smelted raw materials are put into the furnace for a second time to melt into liquid state, and then slag is removed once with 99.99% high-purity argon gas at a slag removal temperature of 730°C for 15 minutes; after slag removal, refining is carried out, the first refining temperature is 735°C for 20 minutes, the second refining aluminum liquid temperature is 740°C for 20 minutes, and the aluminum liquid is allowed to stand for 30 minutes after refining.

[0075] (3) Degassing the raw materials after standing by using an online degassing device, wherein the hydrogen value of the raw materials after degassing is ≤0.15 ml / 100 g; filtering the degassed raw materials, wherein the porosities of the double-layer ceramic filter plates are 40 ppi and 60 ppi, respectively, drying for 1 hour after filtration, casting at a casting speed of 94 mm / min to obtain an aluminum alloy cylindrical ingot, and homogenizing at 560° C. for 12 hours; after homogenization, cooling by strong wind to 200° C., and then cooling to room temperature by water cooling.

[0076] (4) The aluminum alloy cylindrical ingot after homogenization treatment is sawn into fixed lengths, and the outer surface of the aluminum alloy cylindrical ingot is removed by lathing in a cold working state, and the thickness of the removed single side is 3.5 mm.

[0077] (5) The aluminum alloy cylindrical ingot after surface impurities removal is heated and then put into extrusion machine. During the extrusion process, the temperature of the mold on the machine is 480°C, the temperature of the ingot barrel is 380°C, and the aluminum alloy cylindrical ingot is preheated to 485°C before being put into the machine. The extrusion speed is 8.5m / min. Constant speed extrusion is adopted throughout the process. The discharge temperature after extrusion is completed is 525°C.

[0078] (6) The aluminum alloy blank is quenched, wherein the first stage of water mist quenching adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.8 MPa; the second stage of strong wind quenching adopts high-pressure strong wind cooling, and the wind pressure is 1.45 kPa. The temperature of the aluminum alloy blank after leaving the quenching treatment is ≤100°C; after quenching, it is stretched and straightened, and precise digital automatic stretching and straightening are adopted, and the stretching rate is 1.7%, and the stretching time is 20s.

[0079] (7) The alloy blank after stretching and straightening treatment is subjected to a double-stage aging treatment, wherein the temperature of the first aging treatment is 175°C, and the holding time is 10 h; the temperature of the second aging treatment is 195°C, and the holding time is 3 h.

[0080] Example 3

[0081] The aluminum alloy conductor rail profile is composed of the following components by mass percentage: Si 0.38%, Fe 0.09%, Cu 0.01%, Mn 0.01%, Mg 0.54%, Cr 0.01%, Zn 0.01%, Ti 0.01%, the balance is Al and unavoidable impurities, and the total impurity content is ≤0.1%.

[0082] The preparation process includes the following steps:

[0083] (1) A high-purity aluminum ingot with an aluminum content of 99.85% and a high-purity, low-impurity master alloy are placed in a furnace according to the element composition ratio, and the temperature is raised to 730° C. for smelting.

[0084] (2) The smelted raw materials are put into the furnace for a second time to melt into liquid state, and then slag is removed once with 99.99% high-purity argon gas at a slag removal temperature of 730°C for 15 minutes; after slag removal, refining is carried out, the first refining temperature is 735°C for 20 minutes, the second refining aluminum liquid temperature is 740°C for 20 minutes, and the aluminum liquid is allowed to stand for 30 minutes after refining.

[0085] (3) Degassing the raw materials after standing by using an online degassing device, wherein the hydrogen value of the raw materials after degassing is ≤0.15 ml / 100 g; filtering the degassed raw materials, wherein the porosities of the double-layer ceramic filter plates are 40 ppi and 60 ppi, respectively, drying for 1 hour after filtration, casting at a casting speed of 93 mm / min to obtain an aluminum alloy cylindrical ingot, and homogenizing at 560° C. for 12 hours; after the homogenization, cooling by strong wind to 200° C., and then cooling to room temperature by water cooling.

[0086] (4) The aluminum alloy cylindrical ingot after homogenization treatment is sawn into fixed lengths, and the outer surface of the aluminum alloy cylindrical ingot is removed by lathing in a cold working state, and the thickness of the removed single side is 4 mm.

[0087] (5) The aluminum alloy cylindrical ingot after surface impurities removal is heated and then put into extrusion machine. During the extrusion process, the temperature of the mold on the machine is 480°C, the temperature of the ingot barrel is 380°C, and the aluminum alloy cylindrical ingot is preheated to 485°C before being put into the machine. The extrusion speed is 8.5m / min. Constant speed extrusion is adopted throughout the process. The discharge temperature after extrusion is completed is 525°C.

[0088] (6) The aluminum alloy blank is quenched, wherein the first stage of water mist quenching adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.8 MPa; the second stage of strong wind quenching adopts high-pressure strong wind cooling, and the wind pressure is 1.55 kPa. The temperature of the aluminum alloy blank after leaving the quenching treatment is ≤100°C; after quenching, it is stretched and straightened, and precise digital automatic stretching and straightening are adopted, and the stretching rate is 1.5% and the stretching time is 20s.

[0089] (7) The alloy blank after the stretching and straightening treatment is subjected to a double-stage aging treatment, wherein the temperature of the first aging treatment is 170°C, the holding time is 11 h, and the temperature of the second aging treatment is 200°C, the holding time is 3 h.

[0090] Example 4

[0091] The aluminum alloy conductor rail profile is composed of the following components by mass percentage: Si 0.35%, Fe 0.08%, Cu 0.01%, Mn 0.01%, Mg 0.51%, Cr 0.01%, Zn 0.01%, Ti 0.01%, the balance is Al and unavoidable impurities, and the total amount of impurities is ≤0.1%.

[0092] The preparation process includes the following steps:

[0093] (1) A high-purity aluminum ingot with an aluminum content of 99.85% and a high-purity, low-impurity master alloy are placed in a furnace according to the element composition ratio, and the temperature is raised to 730° C. for smelting.

[0094] (2) The smelted raw materials are put into the furnace for a second time to melt into liquid state, and then slag is removed once with 99.99% high-purity argon gas at a slag removal temperature of 730°C for 15 minutes; after slag removal, refining is carried out, the first refining temperature is 735°C for 20 minutes, the second refining aluminum liquid temperature is 740°C for 20 minutes, and the aluminum liquid is allowed to stand for 30 minutes after refining.

[0095] (3) Degassing the raw materials after standing by using an online degassing device, wherein the hydrogen value of the raw materials after degassing is ≤0.15 ml / 100 g; filtering the degassed raw materials, wherein the porosities of the double-layer ceramic filter plates are 40 ppi and 60 ppi, respectively, drying for 1 hour after filtration, casting at a casting speed of 94 mm / min to obtain an aluminum alloy cylindrical ingot, and homogenizing at 560° C. for 12 hours; after homogenization, cooling by strong wind to 200° C., and then cooling to room temperature by water cooling.

[0096] (4) The aluminum alloy cylindrical ingot after homogenization treatment is sawn into fixed lengths, and the outer surface of the aluminum alloy cylindrical ingot is removed by lathing in a cold working state, and the thickness of the removed single side is 3.5 mm.

[0097] (5) The aluminum alloy cylindrical ingot after surface impurities removal is heated and then put into extrusion machine. During the extrusion process, the temperature of the mold on the machine is 480°C, the temperature of the ingot barrel is 380°C, and the aluminum alloy cylindrical ingot is preheated to 485°C before being put into the machine. The extrusion speed is 8.5m / min. Constant speed extrusion is adopted throughout the process. The discharge temperature after extrusion is completed is 525°C.

[0098] (6) The aluminum alloy blank is quenched, wherein the first stage of water mist quenching adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.8 MPa; the second stage of strong wind quenching adopts high-pressure strong wind cooling, and the wind pressure is 1.6 kPa; the temperature of the aluminum alloy blank after leaving the quenching treatment is ≤100°C; after quenching, stretching and straightening are performed, using precise digital automatic stretching and straightening, the stretching rate is 1.5%, and the stretching time is 20 s.

[0099] (7) The alloy blank after the stretching and straightening treatment is subjected to a double-stage aging treatment, wherein the temperature of the first aging treatment is 170°C, the holding time is 11 h, and the temperature of the second aging treatment is 200°C, the holding time is 3 h.

[0100] Comparative Example 1

[0101] The aluminum alloy conductor rail profile is composed of the following components by mass percentage: Si 0.42%, Fe 0.2%, Cu 0.05%, Mn 0.05%, Mg 0.68%, Cr 0.1%, Zn 0.1%, Ti 0.1%, and the balance is Al and unavoidable impurities, and the total impurity content is ≤0.1%.

[0102] The preparation process includes the following steps:

[0103] (1) A high-purity aluminum ingot with an aluminum content of 99.85% and a high-purity, low-impurity master alloy are placed in a furnace according to the element composition ratio, and the temperature is raised to 730° C. for smelting.

[0104] (2) The smelted raw materials are put into the furnace for a second time to melt into liquid state, and then slag is removed once with 99.99% high-purity argon gas at a slag removal temperature of 730°C for 15 minutes; after slag removal, refining is carried out, the first refining temperature is 735°C for 20 minutes, the second refining aluminum liquid temperature is 740°C for 20 minutes, and the aluminum liquid is allowed to stand for 30 minutes after refining.

[0105] (3) Degassing the raw materials after standing by using an online degassing device, wherein the hydrogen value of the raw materials after degassing is ≤0.15 ml / 100 g; filtering the degassed raw materials, wherein the porosities of the double-layer ceramic filter plates are 40 ppi and 60 ppi, respectively, drying for 1 hour after filtration, casting at a casting speed of 96 mm / min to obtain an aluminum alloy cylindrical ingot, and homogenizing at 550° C. for 10 hours; after homogenization, cooling by strong wind to 200° C., and then cooling to room temperature by water cooling.

[0106] (4) The aluminum alloy cylindrical ingot after homogenization treatment is sawn into fixed lengths, and the outer surface of the aluminum alloy cylindrical ingot is removed by lathing in a cold working state, and the thickness of the removed single side is 4 mm.

[0107] (5) The aluminum alloy cylindrical ingot after surface impurities removal is heated and then put into extrusion machine. During the extrusion process, the temperature of the mold on the machine is 480°C, the temperature of the ingot barrel is 380°C, and the aluminum alloy cylindrical ingot is preheated to 480°C before being put into the machine. The extrusion speed is 4m / min, and the discharge temperature after extrusion is completed is 525°C.

[0108] (6) The aluminum alloy blank is quenched, wherein the first stage of water mist quenching adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.8 MPa; the second stage of strong wind quenching adopts high-pressure strong wind cooling, and the wind pressure is 1.45 kPa. The temperature of the aluminum alloy blank after leaving the quenching treatment is ≤100°C; after quenching, it is stretched and straightened, and precise digital automatic stretching and straightening are adopted, and the stretching rate is 1.5%, and the stretching time is 20s.

[0109] (7) The alloy blank after the stretching and straightening treatment is subjected to a double-stage aging treatment, wherein the temperature of the first aging treatment is 170°C, the holding time is 11 h, and the temperature of the second aging treatment is 200°C, the holding time is 3 h.

[0110] The aluminum alloy conductive rail profiles prepared in Examples 1-4 and Comparative Example 1 were tested for performance, and the results are as follows:

[0111] Table 1 Performance of aluminum alloy conductor rail profiles

[0112]

[0113] It can be seen from Table 1 that the performance of the aluminum alloy conductive rail profiles prepared in Examples 1-4 is significantly improved compared with that in Comparative Example 1, wherein the tensile strength is ≥215 MPa, the yield strength is ≥168 MPa, the elongation is ≥11%, and the conductivity is ≥55.3 IACS%, which can meet the production requirements of the aluminum alloy conductive rail profiles.

[0114] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing an aluminum alloy conductive rail profile, characterized in that: The following steps are involved: (1) The raw materials are put into a furnace for melting according to a formula, wherein the aluminum alloy conductive rail profile is composed of the following components by mass percentage: Si 0.34%-0.39%, Fe 0.08%-0.09%, Cu≤0.01%, Mn≤0.01%, Mg0.5%-0.55%, Cr≤0.01%, Zn≤0.01%, Ti≤0.01%, and the balance is Al and unavoidable impurities, and the total amount of impurities is ≤0.1%, wherein Mg:Si=(1.41-1.47):1; (2) slagging, refining, and standing the smelted raw materials; (3) degassing and filtering the raw materials after standing, casting to obtain an aluminum alloy cylindrical ingot, and homogenizing the ingot; wherein the casting speed is 90 mm / min-95 mm / min, the temperature of the homogenization treatment is 555° C.-565° C., the time is 11 h-13 h, and the aluminum alloy cylindrical ingot after the homogenization treatment is subjected to a strong wind cooling treatment, cooled to 190° C.-210° C., and then cooled to room temperature by water cooling; (4) removing impurities from the surface of the aluminum alloy cylindrical ingot after homogenization; (5) heating the aluminum alloy cylindrical ingot after surface impurities removal and extruding it on a machine to obtain an aluminum alloy blank; wherein the machine temperature of the aluminum alloy cylindrical ingot is ≥ the machine temperature of the mold, the mold machine temperature during the extrusion process is 475° C.-485° C., the ingot barrel temperature is 375° C.-385° C., the temperature of the aluminum alloy cylindrical ingot is 480° C.-490° C., the discharge temperature of the aluminum alloy blank after extrusion is 522° C.-530° C., the extrusion process is constant speed extrusion, and the extrusion speed is 5 m / min-10 m / min; (6) quenching and cooling the aluminum alloy blank, and then stretching and straightening the blank; the quenching treatment includes a first stage of water mist quenching treatment and a second stage of strong wind quenching treatment; the first stage of water mist quenching treatment adopts multi-angle high-pressure precision water mist online quenching, and the water mist pressure is 0.6MPa-1.0MPa, and the second stage of strong wind quenching treatment adopts high-pressure strong wind cooling, and the wind pressure is 1.45kPa-1.6kPa, and the temperature of the aluminum alloy blank after leaving the quenching treatment is ≤100°C; (7) subjecting the alloy blank after the stretching and straightening treatment to aging treatment, wherein the aging treatment adopts a two-stage aging treatment process; the temperature of the first-stage aging treatment is 165° C.-175° C., and the holding time is 10.5 h-11.5 h; the temperature of the second-stage aging treatment is 195° C.-205° C., and the holding time is 2.5 h-3.5 h; The aluminum alloy conductive rail profile has a tensile strength of ≥217MPa, a yield strength of ≥170MPa, an elongation of ≥13.4%, and a conductivity of ≥55.6IACS%; The aluminum alloy conductive rail profile includes an upper horizontal rail, a vertical rail and a lower horizontal rail. The vertical rail is provided with a heat sink, the bottom of the lower horizontal rail is provided with a T-slot, and a reinforcing rib is provided between the bottom of the upper horizontal rail and the vertical rail. The ratio of the thickness to the length of the heat sink is 1 / 7-1 / 5.

2. The method for preparing the aluminum alloy conductive rail profile according to claim 1, characterized in that: In step (4), the surface de-impurity includes removing the outer surface of the aluminum alloy cylindrical ingot in a cold working state, and the thickness of the single-side removal is 3mm-5mm.

3. The method for preparing the aluminum alloy conductive rail profile according to claim 1, characterized in that: In step (6), the stretching and straightening treatment adopts precise digital automatic stretching and straightening, the stretching rate is 1.3%-1.8%, and the stretching time is 18s-22s.

4. The method for preparing the aluminum alloy conductive rail profile according to claim 1, characterized in that: In step (3), degassing is performed by an online degassing device, and the hydrogen value of the raw material after degassing is ≤0.15ml / 100g; The filtration is carried out using a double-layer ceramic filter plate, the porosity of the ceramic filter plate is 40ppi and 60ppi respectively, and the filtration is followed by drying for 1h-1.5h.

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